hey guys im getting a vibration coming somewhere from the rear. mainly does it if im stopped and go to turn, and does it very slightly i i accelerate in a straight line. any ideas?

 

have you ever replaced your rear diff fluid? i assume you have a l/s differential and it is time to change the fluid. don't forget friction modifier.

post your rear end, gear ratio, and whether open or limited slip first though.

 

3.55 ls and just changed it at 100,000 miles and im at 135,000 now. i did put friction modifier in. one tube of it

 

next thing to check is u-joints.

 

Does it happen when you accelerate to pass someone on the highway?

 

nah. pulled the fill plug yesterday to find all grey/metallic colored "sludge" built u[p on the plug and inside along with metal particles. so im guessing the clutch packs are shot. gonna have a friend who owns a trans/rear shop do it in about a week

 

hey mine started doing that this morning. i figured it out that it only happens durring lock up. (when in overdrive) and when i want to pass someone on the frwy or just slight accelerate i feel vibrations only during the downshift. could it be my diff having too much play? help plz!

 

Are you sure it's not a COP issue? Are you getting a MIL when this happens?

 

no on both counts

 

By the way, it takes 2 bottles of friction modifier for a 2000 model. The clutch packs are tight. There is a TSB on this. The official Ford fix is to replace the clutch pack and reduce the shimming by 0.010". The fix the parts guy told me about was to use 2 bottles of FM. He said that is what most people did. I did and it worked.

 

mine does this only in a straight line and only when I come to a full stop than acclerate. Doesn't happen very long and its not super noticable. If i accelerate slow enough/fast enough its not noticeable. Its fine when turning and everywhere else. The Diff fluid was replaced about 10K kms ago. Any idea?? 2006 F150 FX4 3.73

 

Just running thru threads, but I am sort of in the same spot but I get a very noticeable vibration only when at a dead stop turning in both directions. The vibration is clearly in the rear and not up towards the tranny. Its always slightly been there I think, but over the last week its gotten way worse. Any thoughts?

 

Refer to the new thread you started.